This invention relates generally to a lever handle assembly for use with locks, and more particularly to a lever handle assemble for use with mortise locks.
One form of a lever handle assembly that has been used in the past has included a threaded inside spindle having a square cross section which was threaded onto a reduced male portion of an outside spindle to which the outside lever was attached by a roll pin. The inside lever was threaded onto the threaded inside spindle until it comfortably fit within the bushing portion of an adapter plate which was mounted on the door. The inside lever was secured to the inside spindle by means of set screws which bottomed out on the flat portion of the spindle. The levers were used to operate the latch bolt of a mortise lock.
The threaded spindle provided a means for adjusting the axial position of the lever to compensate for various door thicknesses. However, the torque caused by repeated turning of the lever handle could result in the set screw damaging the spindle and the lever handle could work loose. Additionally, due to machining requirements in forming the reduced threaded male portion on the outside spindle, an undercut was provided at the point the male portion joined the outside spindle body. If the gap between the inside and outside spindle heads was not properly maintained, upon operating the lever, the two spindles could bind, and excessive force and pressure on the lever could cause the outside spindle to fail at the undercut.